FAYETTEVILLE, N.C. -- Police in Fayetteville told 2 Wants To Know that counterfeit money is on the rise in their area.

Police said the fake 100 dollars bills are such high quality that some banks aren't even catching them. However, the $20 bill is the most commonly counterfeited bill in the U.S.

So how do you make sure the money in your wallet is real? Hold each bill up to the light. When you're looking at the 20 dollar bill, the security strip will be on the left side of the dollar. In the light - you'll see it says 'USA TWENTY' on it. This is the case for all 20 dollar bills made after 2003.

You also want to touch the bill. You should feel raised printing on it.

Another option is to buy a counterfeit marking pen. This will really come in handy if you're dealing with large bills a lot or if you're having a garage sale. If the bill is real, the ink turns yellow. If it's fake, it turns dark blue or black. You can buy one on Amazon or at Staples for about 5 bucks. One thing to keep in mind - Fayetteville police say depending on what paper the fraudster used, the pen might not work.

UScurrency.gov shows all of the dollar bills and how to make sure they're real.